Problem: What do the following two equations represent? $-2x-4y = -2$ $-2x-4y = 4$
Answer: Putting the first equation in $y = mx + b$ form gives: $-2x-4y = -2$ $-4y = 2x-2$ $y = -\dfrac{1}{2}x + \dfrac{1}{2}$ Putting the second equation in $y = mx + b$ form gives: $-2x-4y = 4$ $-4y = 2x+4$ $y = -\dfrac{1}{2}x - 1$ The slopes are equal, and the y-intercepts are different, so the lines are parallel.